Metal casting



Aug. 4, 1959 N. B. ORNITZ- METAL CASTING Filed Sept. 19, 1956 a ix i INVENTOR.

Nathaniel B. Ornitz United Sttes Patent METAL CASTING Nathaniel B. Ornitz, Golden Beach, Fla, assignor to Blaw-Knox Company, Pittsburgh, Pa., a corporation of Delaware Application September 19, 1956, Serial No. 610,776

17 Claims. (Cl. 22216) This invention relates to metal casting and particularly to a method of reducing the amount of segregation and the amount of dissolved gases and porosity and of improving the physical properties of the resultant metal.

The problem of eliminating segregation in metal casting'has long plagued the metal founding and treating industries. This undesirable segregation and similar inhomogeneities are the source of many failures in metal products as cast or after forging,.rolling or similar working. Many attempts have been made to solve this problem but without any real and consistent success.

I have discovered a method of reducing casting inhomogeneity and producing cast metals of significantly more homogeneous structure than has been heretofore possible. I have found that more homogeneous metal can be produced by inserting a fusible metal member into the molten mass and subjecting said metal member to vibrations.

I have found that the metal member should be made of a metal of approximately the same composition as the bath being treated or at least compatible therewith and have a melting point such that it is substantially but not necessarily entirely dispersed or dissolved in the molten mass during treatment. A conical shape is a preferred form of the member in order to regulate solution of the member in the mass being treated and thereby permit the member to remain active until final solidification of the mass by preventing any limiting of the effectiveness of the vibration during final stages of solidification.

, Preferably the metal member is subjected to vibrations until the mass, is substantially solidified. There are, however, instances where vibration may be interrupted prior to complete solidification. For example, where a homogeneous outer surface alone is desired, the vibration may be interrupted as soon as solidification has proceeded to the required surface depth. Where only the reduction of gases is desired, vibration may be interrupted as soon as the desired reduction in the amount of gases is attained.

The vibrations which are applied to the member can vary from 25 cycles to 500,000 cycles but are preferably in the ultrasonic range and particularly in the range of 10,000 to 300,000 cycles per second. These vibrations may be applied in any of the known ways, as for example, by electrical means, e.g., magnetostriction devices, mechanical, hydraulic or other means.

In the foregoing general description I have set out certain objects, purposes and advantages of this invention. Other objects, purposes and advantages will be apparent from a consideration of the following description of a preferred embodiment of my invention and the accompanying drawings in which:

Figure 1 is a side elevation of a vibrating cone suitable for use in the invention.

Figure 2 is a section through a mold showing the vibrating cone in position in the molten mass.

Referring to the drawings, 1 have illustrated a cone of a metal having approximately the same composition as the metal bath in which it is to be used, or alterna tively, of a composition which is compatible with that of the molten mass in which it is to be used and whose melting point is such that it will be consumed in the body of metal to form a substantially homogeneous final cast. The metal cone is threaded at the base thereof onto a magnetic transducer 11 of conventional construction connected to a conventional power source for the production of vibrations. The cone 10 is inserted in the bath 12 of molten metal so that the tip 13 of the cone 10 is slightly above the bottom of the mold 14. The cone 10 preferably is subjected to vibrations at frequencies of about 25,000 cycles per second. The cone is of dimensions such that vibrations are transmitted to the molten mass throughout its entirety. As the molten mass cools, the continuous vibration through the conical transmitter causes the homogeneous distribution of materials throughout the mass and a slow and continuous distribution of the cone itself into the mass as it is fused by the molten metal. The conical shape is such that it regulates the fusion of the cone into the mass as the material in the mold solidifies so that the central surface portion which is the last to solidify is subject to vibration until the complete solidification occurs and the cone is fused or immobilized.

In large masses of metal it may be desirable to use several spaced fusible members inserted into the molten mass instead of a single member as discussed above. Such spaced members should be so spaced and have dimensions such that vibrations transmitted to them are communicated to the entire mass of molten metal.

While I have illustrated and described certain preferred embodiments of my invention, it will be understood that it may be otherwise embodied within the scope of the following claims.

I claim:

1. The method of forming homogeneous cast metal structures comprising the steps of pouring molten metal into a mold, inserting a metal member fusible at the temperature of the molten metal into the molten mass and subjecting said metal member to 'vibrations.

2. The method of forming homogeneous cast metal structures comprising the steps of pouring molten metal into a mold, inserting a metal member fusible at the temperature of the molten metal into the molten mass and subjecting said metal member to vibrations until at least .aportion of the mass is solidified.

3. The method of forming homogeneous cast metal structures comprising the steps of pouring molten metal into a mold, inserting a fusible member of substantially the same composition as the metal mass into said molten mass and subjecting the metal member to vibrations.

4. The method of forming homogeneous cast metal structures comprising the steps of pouring molten metal into a mold, inserting a fusible member of substantially the same composition as the metal mass into said molten mass and subjecting the metal member to vibrations until at least a portion of the mass is solidified.

5. A method of forming homogeneous cast metal structures comprising the steps of pouring molten metal into a mold, inserting a metal member fusible at the temperature of the molten metal into the molten mass to a point adjacent the bottom of the molten mass and subjecting the metal member to vibration until the mass is substantially solidified.

6. The method of forming homogeneous cast metal structures comprising the steps of pouring molten metal into a mold, inserting a fusible metal member of substantially the same composition of the metal mass into the molten mass and subjecting the metal member to vibration at frequencies in excess of about 10,000 cycles.

7. The method of forming homogeneous cast metal structures comprising the steps of pouring molten metal into a mold, inserting spaced fusible metal members into the molten mass, said members being so spaced and having dimensions such that vibrations transmitted thereto are communicated to the entire mass of molten metal and subjecting the metal members to vibrations.

8. The method of forming homogeneous cast metal structures comprising the steps of pouring molten metal into a mold, inserting spaced metal members fusible at the temperature of the molten metal into the molten mass, said members being so spaced and having dimensions such that vibrations transmitted thereto are communicatcd to the entire mass of, molten metal and subjecting the metal members to vibrations until the mass is at least partially solidified.

9. The method of forming homogeneous cast metal structures comprising the steps of pouring molten metal into a mold, inserting a generally conical metal member fusible at the temperature of the molten metal into the molten mass and subjecting said metal member to vibrations.

10. The method of forming homogeneous cast metal structures comprising the steps of pouring molten metal. into a mold, inserting a conical metal member fusible at the temperature of the molten metal into the molten.

mass, said cone having a dimension sufficient totransmit vibration therefrom to the entire mass of the molten metal and subjecting the metal cone to vibration.

ll. The method of forming homogeneous cast metal structures comprising the steps of pouring molten metal into a mold, inserting a generally conical member of substantially the same composition as the metal mass into said molten mass and subjecting the metal member to vibration at frequencies in excess of about 10,000. cycles.

12. The method of forming homogeneous cast metal structures comprising the steps of pouring molten metal. into a mold, inserting a fusible generally conical metal member of substantially the same composition as the molten mass into the molten mass, said cone having a dimension sufiicient to transmit vibration therefrom to the entire mass of the molten metal and subjecting the metal cone to vibration until the molten mass is at least partially solidified.

13. The method of forming homogeneous cast metal structures comprising the steps of pouring molten metal into a mold, inserting a generally conical metal. mem.- ber fusible at the temperature of the molten metal and, of a composition compatible with the molten mass into the molten mass, said cone having a dimension suificient to transmit vibration therefrom to the entire mass of the molten metal and subjecting the metal cone to. vibration until the mass is at least partially solidified.

14. The method of forming homogeneous cast metal structures comprising the steps of pouring molten metal into a mold, inserting spaced generally conical members fusible at the temperature of the molten metal into the molten mass, said cones being so spaced and having dimensions such that vibrations transmitted thereto are communicated to the entire mass of molten metal and subjecting the metal cones to vibration.

15. The method of forming homogeneous cast metal structures comprising the steps of pouring moltenmetal into amold, insertingspaced generally conical members fusible at the temperature of the molten metal intothe molten mass, said: cones; being; sospaced and having dimensions such that vibrations transmitted thereto are communicated to the entire mass of molten metal and subjecting the metal cones to vibration until the molten mass is at least partially solidified.

16. The method of forming homogeneous cast metal structures. comprising the steps of pouring molten metal into a mold, inserting; spaced generally conical. members of substantially the, same composition as the molten mass. into. the molten mass, said cones being so spaced and having dimensions such that vibrations transmitted there-- to. are communicated to, the entire mass of moltenmetaland subjectingthe metal cones to vibration.

17.v The method of forming, homogeneous cast metal, structures comprising the, steps. of. pouring molten metal into a mold, inserting a generally conical metal member fusible at the temperature of the molten. metal into. the molten mass, said cone having a dimension sufficient to transmit vibration therefrom. to. they entire mass-of the molten. metal and subjecting the, metal cone to vibration until the mass. is substantially solidified and the mass. of the. cone. has, been substantially distributed in the solidified mass.

References Cited in the. file of this patent UNITED STATES PATENTS 1,053,73'8- McNifi Feb; 18, 1913' 1,715,859 Hultgren Sept. 16; 1930- 1,939,712 Mahoux Dec; 19, 1933 2,301,947 H'annen Nov. 17, 1942' OTHER REFERENCES Metallurgia, vol; 47, No; 281', March 1953. Pages Journal on the. Acoustical Society of America, vol. 26; No. 5,.September 19.54. Pages 831-842. 

